Telegraph cipher system



-Uct. 9, 121528.

G. S. VERNAM TELEGRAPH CIPHER sYsTEH Filed 001'.. 31', 1925 VVENTOR 6'. ,er

ATTORNEY 20 combinations of l tape printer.

dmanr s. vnmmm, or ama nnen, Naw JERSEY; assrenoa'ro IIE a man 'rn- PEQNE AND TELEGRAPH GOMPAN`Y, A CORPORATION 0F NEW YORK.

rnnn'eaarn enana SYSTEM.

Application led etober 31, 1925. Serial No. 66,114.

Y Tins invention relates to telegraph systems and more particularly to improvements in such systems whereinprinting telegraph lapparatus is utilized and in which the signals are transmitted in scrambled or unintellible cipher formation for purposes of secrecy.

In a Patent #1,310,719, issued July22, 1919 toG. S. Vernam, there is illustrated a well known secret telegraph signaling sys- 1 0 tem. In this system the characters of the are made up of various com-` message which binations of the elements of a iive'unit code, are combined in eiect 'th the code combinations of a key tape'and the resultant code combinations' make up an enciphered and unintelligible message which is transmitted to a distant station. At the receiving station the code combinations of the unintelligible message are combined in eect with the code akey tape identical to that at the sending station and the resultant code combinations will form the original message in intelligible formation', or -p ain-text. It has been one of the practices with the above referred to system to set up these plain text five unit code combinations at` the receiving station on five selecting magnets and to thereby operate rinting telegraph receiving mechanism we known in ,the art. However, it

has been found in certain types of service that it would be undersirable to always utilize ive magnet printing telegraph receivers and that conditions would arise wherein .it would be more desirable to utilize a printing telegraph 35. receiver of the type operated by .only a single selective magnet.. Accordingly, the primary object of this invention consists in providing at the receiving end of a secret telegraph system .of the above type a translating device en whereby the incoming five unit code combination may be de'ciphered and then utilized to operate a single magnet responsive device, such as a printing telegraph receiver of the single selectiveA magnet type. This device is also suitable to be inserted at any. point along a circuit `for automatically enciphering` or deci hering meages passing through and Y sen them on over the rest of the circuit. In suc cases a repeating relay would be used 'dan instead ofa printer.

The single selective magnet type of'printer is well known in the art and for purposes of illustration a speciiic machine of this charac.- ter may be found in the Morkrum teletype Such apparatus is described 1n ceivlng di'um of a single magnet, the operation of the scribed for purposes of an application filed in the S. Patent ce oli-December 23, 1919, Serial No. 346,948, in

the names of Charles L. Krum and Howard tion for complete details of the arrangements. However, a general description of the receiv- L. Krum. Reference is made to thisapplicaing mechanism of thev deviceis givenherein. Y The received impulses which make up'units of the five unitcode ,combinations are-caused to .operate the single magnet oftheteletype printer. The prlnter is' controlled by this magnet which operates an armature moved in' one direction by the magnet and in the opposite direction by,v an adjustable spring.

The printer mehanism is carried by asuitable frame, the moving parts of which are operated from a motor through the medium oa start 'and stop clutch which is initiated 1n. operation by the starting impulse or infterval of each signal. A' rotating'selector actuator driven by the motor and thrown into operation by the clutch is adapted to position a set of selectors in different gombinations in accordanceJwith the movement of the armature of the controlling magnet, and which 1n turn is controlled by the combinations of impulses coming in. The shaft carrying the fer-cam Vwhich at each rotation transfers thev setting of the selectors or seekers and restores the first set for/the next operation. The main shaft which carries the selector actuator also carries a combiner wheel, a notched ratchet 'selector-actuator is also provided"with atranswheel and a type wheel. Theseekers cooperstation thus controls through the meprinter mechanism to secure the impression of the characters' represented by the signals upon a paper strip. It is'understood that the arangements of the invention may be utilized with other ty es of single magnet and that' the a ove specific type has een de- -illustration only. Furthermore,-if a repeating relay were utilrinters lll@ ized with the arrangements ofthe invention, the repeated impulses might be transmitted further along the circuit and utilized to operate any other type of printer mechanism.

The invention may be more fully. underf' stood vfrom the following description together with the accompanying drawing in the fgure of which is a circuit diagramI embodying the principles of the invention. .In the drawing are shown the arrangements at a receiving station. At the sending station,

there might be provided sending apparatus similarto that illustrated in the above men#` tioned patent to G. S. Vernam. In this sending apparat-us thecharacters of the originalmessage would be composed of five unit code might be done either by a radio or wire sys-l tem. At the receiving station, these incoming code combinations ywould be received over a local'line circuit illustrated as circuit 7 and the line relayl 8 included therein would be actuatedbyt ese units of the code combinations. Associated 'With the contacts of the line relay 8 is afbattery 16 and the contacts of a tapetransmitter 9. In the tape transmit-V midpoint of that the armature 414 of' the ter 9 would be inserteda key ta identical with the key ta e used for encip ering purposes at th'e sending station. The contacts of the key Atape transmitter are connected to segments of adistributor- 10. Other connectionsl are made from the distributor to a polar relay 13 and further connections from the battery16 andthe contacts of the-mpolar relay 13 are provided `to the mao'net 18A cf a printer 17, which is` of the heretoore mentioned single magnet typ'e. 'When a starting signal, which consists o an o en pulse, is received over line circuit 7,

the hne relay 8 will release and close the fol-- lowing circuit, from positiva pole of battery 16, conductor 20,' segment 21, brush 11, segment 22,l winding of start m et 12, conductor'23, contact o relay 82 to t e negative pole of battery 16. This'will-operate the start m et'12 which will release the brush 11 of t e distributor'and allow it'to commence its travels across the `distributor segments. gvlllien the brush 11 tlzoucies b h o Owing' circuit is c ose ,segment 24, rus

' ent 25, windings of' polar' relay 13,

dresistance 15, conductor $1, batte 16 con uctor28 tot 24. v. e polaiiyty 0,1 the current dow in this circuit is such polar rela 1 3 willbemovedtoitsspacinf contact .Se. 18, i;

re 'magn o am prima rimani@ will sliort. circuit and the printer a i As has been midpoint of rductor 27 to pointed out the key tape will have caused to be set up on the contacts of the tape transmitter 9 the key code combination corresponding to the cipher code combination being received. Accordingly, as the brush 11 passes over segment 1 the signal. on

the line at that instant will combine in 'eect with the selection 1 of the tape transmitter contacts to operate the polar relay13 in the following manner:

' (1) If the line signal is'marking operated) and the tape'transmitter contact 1- is against the right-hand or marking bus-bar, the polar relay armature will be moved to its spacing contact. This is due to the fact-that under; such conditions the circuit closed through the polar relay will be as follows: negative pole of battery 16, conductor 30, contact of relay 8, conductor. 81, right-hand busbar, contact 1, conductor 32, segment 1, brush 11, segment 25, windings of polar relay 13,

resistance positive pole of battery 16.

(12) If the line signal is spacing (relay8 released) and the tape transmitter contact 1 is against the leftfhand or s acing bus-bar, the -polar relay armature will) be moved to its 15, conductor 26, to

(relay 8 spacing contact. This is due to the fact that under such vconditions the circuit closed through the polar relay windings is as follows: negative poleof battery 16, conductor 30, contact of relay 8, conductor 34, leftlhand bus-bar, contact 1', conductor 32, segment 1, brush 11, segment 25, windings of relay 13, midpoint of resistance 15, conductor 26, to positive wle of battery 16.

. (3) I the line signal is marking and the key tape selection is spacing, the polar relay armature .will move to its marking contact. This is due to the fact that under such con# ditionsthe circuit closed through the polar relaywindings is as follows: positive pole of battery16, contact of re1ay`8 conductors 33 and 34, left-hand bus-bar, contact 1','con ductor 32, segment 1, brush `11, ent 25, windings ofl polar. relay 13, midpoint of resistance 15, conductor 27, to negative pole of battery 1 6."

(4) If the line signal is s ac' and the key selection marking, the po ar re ay armature will move to the marking side. This is due to the fact that under such conditions the circuit closed through the polar'relay wind- Aings isA asfollows: positive pole of battery 16contact of relay 8, conductor 35, handbus-'bar contact 1', conductor 32, segment 1,- brush. 11 segment 25, windings of pour muy is, mipo resistancel 15, oonmgm mi? fb.

6 0 tte L16. :nvm "notgdfmpo ry ofmagnet 18 is sh magnet 18 .of relay-13 'is on its 'cuit is completed from battery- 16 om coli- Tuo lll'

when the armature of ductors 26 and 27 and over the marking contact and armature of relay 13 through the winding of 'magnet 18, thereby operating magnet 18.

When the brush 11 moves on over segments 2, 3, 4 and 5, the key tape selection on the transmitter will combine With the incoming signal in the same manner as already described with respect to segment 1 and contact 1 of the transmitter.

After each of the segments 1, 2, 3, 4 and 5 are provided the segments 36', 37 38, 39 and A 40. These segments are connected through a Vcommon conductor 41 and a high resistance 42-tol the armature of the polar relay 13. Accordingly, when the brush passes over these l segments 36, 37, 38, 39 and 40, a locking ciry 'of'embodiment in many other forms WithoutA cuit is provided for the polarrclayl to hold it operatedwhile the brush is passing between the operating Segments 1, v2, 3, 4 and 5.

When the brush passes over segment 6, the following circuit will bc closed.' from positive pole of battery 16, conductor 26` winding of stepping magnet 19, segment 6, brush 11, segment 25, winding of polar relay 13, midpoint of resistance 15, conductor 27, to nega-A tive pole of battery 16. This will cause the polar relay armatureto move to its marking contact and hence close the operating circuit for the magnet 18 so that a stop Iimpulse may be sent into the printer. The steppingl magnet 19 will also be operated to step the key tape of the transmitter ahead one step.

While the arrangement has been disclosed in certain specific forms which are deemed desirable, it is understood that it is capable departing from the spirit of the invention as defined by the appended claims.

Whatis claimed is 1. The method of deciphering and receiving aA secret message, which consists in combining the electricaleffect of the received impulses with the effect ofthe electrical conditions representing a deciphering character to produce electrical impulses representing the message character, and causing said message character impulses to individuall and sequentially operate a single responsive device.

2. In a secret signaling system in which the electrical impulses transmitted as the' secret message are produced by combining the effect of electrical conditions representing the original message character withthe effect of electrical conditions representing a ciphering character, a receiving set comprising means for combining the electrical efect of the received impulses with the eii'ect of electrical conditions representing a deciphering character to produce electrical impulses repre,- senting the original message character, a vrelay, and timing mechanism for applying said last mentioned electrical impulses sequentially to said relay.

3. In a secret signaling system in which the electrical impulses transmitted as the secret message are produced by combining the effect of electrical conditions representing the originalmessage character 'with the effect of elec trical conditions representing a. ciphering character, a receiving set comprising a receiving relay responding to the electrical impulses comprising the secret message, a key tapetransmitter having its contacts setto representthe ciphering character utilized to produce the secretI message, circuits controlled by said receiving relay and said transmitter contacts to reproduce a set of electrical conditions representing the original message character,

a polar relay, a distributor to sequentially ap- October, 1925.

' GILBERT S. VERNAM. 

